There is a general demand for efficient identification of a wireless device in a wireless communication environment. More specifically, there is a need for generating an identifier for a wireless device and for identifying a wireless device in a wireless communication environment.
There may also be a need for exchanging information between different types of wireless networks based on the identification of a wireless device, and/or for linking context information of a wireless device between different types of wireless networks, and/or for supporting access selection and/or mobility decision for a wireless device in a wireless communication environment. By way of example, this is relevant in a wireless communication environment including a cellular radio communication network and a Wireless Local Area Network, WLAN, to enable efficient interworking between a cellular network and a WLAN such as a Wi-Fi network.
By way of example, mobile operators are today mainly using Wi-Fi to offload traffic from the mobile networks but the opportunity to improve end user experience regarding performance is also becoming more important. The current Wi-Fi deployments are mainly totally separate from mobile networks, and are to be seen as non-integrated. The usage of Wi-Fi is mainly driven due to the free and wide unlicensed spectrum, and the increased availability of Wi-Fi in mobile terminals like smartphones and tablets. The end users are also becoming more and more at ease with using Wi-Fi for example at offices and homes.
The different business segments for Wi-Fi regarding integration possibilities can be divided into mobile operator hosted/controlled vs. 3rd party hosted/controlled Wi-Fi APs (here 3rd party is seen as anything else than mobile operator and that the 3rd party is not totally “trusted” by the mobile operator. 3rd party could be for example a Wi-Fi operator or an end-user him/herself). In both segments there exist public/hotspot, enterprise and residential deployments.
Wi-Fi integration towards the mobile core network is emerging as a good way to improve the end user experience further. These solutions consist mainly of the components: common authentication between 3GPP and Wi-Fi, and integration of Wi-Fi user plane traffic to the mobile core network. The common authentication is based on automatic SIM-based authentication in both access types. The Wi-Fi user plane integration provides the mobile operator the opportunity to provide the same services, like parental control and subscription based payment methods, for the end users when connected both via 3GPP and via Wi-Fi. Different solutions are standardized in 3GPP: Overlay solutions (S2b, S2c) are specified since 3GPP Rel-8 while integration solutions (S2a) are currently work-in-progress (S2a, S2b, S2c indicating the 3GPP interface/reference point name towards the PDN-GW). These solutions are specified in 3GPP TS 23.402.
For example, a mobility decision normally requires that both the context of a wireless device such as a UE or mobile station in the cellular network and the WLAN are available in order to take an optimum access selection decision. Currently, the only common UE identifier in both the cellular network domain and the WLAN domain is the International Mobile Subscriber Identity, IMSI. The problem is that the IMSI is not available before EAP authentication is initiated, and hence the mobility decision entity needs to have the wireless device perform an Open System Authentication in WLAN in order to obtain the IMSI and link the context of the wireless device in WLAN to the context in the cellular domain. This approach takes time and normally leads to inefficient usage of resources. For example, a wireless device such as a UE could be denied access to WLAN by the mobility decision function; and even though access has been denied and the UE is not using the WLAN network, it still had to connect and send several Over-The-Air, OTA, messages. Furthermore, for security purposes most wireless devices such as UEs nowadays will not expose their permanent identity, i.e. IMSI, and this generally prevents the WLAN network from obtaining the permanent identity right away.